Piston ring



March 14, 1944. w S LQEB 2,343,915

PISTON RING Filed April 23, 1942 S'Sheets-Shet 1 I INVENTOR.

J19 I BY fl 7 1mg March 14, 1944. w. s. LOEB PISTON RING Filed April 23, 1942 3 Sheets-Sheet 2 INVENTOR.

- -March 14, 1944. w 5, LQEB 2,343,915

- I PISTON RING Filed April 25, 1942 r 3 Sheets-Sheet 3 Batente'cl Mar. 14,

PISTON arm's William s. Loeb, Philadelphia, 1a., assignor to Wilkening Manufacturing Company, Philadelphia, Pa., a corporation'of Delaware Application April 23, 1M2, Serial No; 440,184

20 Claims.

The present invention relates to certain new and useful improvements in piston rings and it relates more particularly to a novel construction for piston rings adapted for use in internal.

. combustion engines.

An object of the .present invention is to provideasimple, inexpensive and efficient piston ring for internal combustion engines.

Another object of the present invention is to provide a composite oil-controlpiston ring made up of a plurality of interchangeable circumferentially-disposed and interlocked segments, dis-. posed in self-interlocking and form-retaining relationship.

With the above and other objects and purposes Y in view as will be apparent in the following specification, appended claims and accompanying drawings, the present invention comprises a I novel self-expanding oil-control piston ring composed of a plurality of interchangeable segments formed of sheet metal or the like, suitably bent and folded to provide oil-passageways therethrough, said segments being removablyinter-,

locked with one another and being adapted to be disposed within the groove of a piston with the oil-passageways extending radially of said piston.

For the purpose of illustrating. the invention,

there are shown in the accompanying drawings forms thereof which are-'at present preferred,

Y since the same have been found inpractice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to theprecise arrangementsand organizations of the instru 'mentalities as herein shown and described.

Referring to the accompanying drawings in which like reference characters indicate like parts throughout: m

Figure 1 represents a perspective view of one. embodiment of the present invention, shown in compressed installed position.

Figure 2 represents a fragmentary perspective view, on a' greatly enlarged scale, of the 5 embodiment shown in Figure 1; parts being broken away better to reveal the construction thereof.

Figure 3 represents a perspective view, onan enlargedscale, of one of the segments making up the embodiment illustrated in. Figure 1.

'- Figure 4 represents a perspective view similar to Figure 3 but showing one of the segments as it appears when rotated vertically through Figure 5 represents a vertical cross sectional u with saidbase 2| view, on an enlarged scale, generally along the line 5-5 of Figure 1.

Figure 6 representsan end view, on an enlarged scale, generally in the direction of the arrows 6--6 in Figure 1.

Figure 7 represents a vertical cross-sectional view generally along the line 1-1 ofFigure -5 Figure 8 represents a perspective view, on an enlarged scale, of a modified form of segment as used in another embodiment of the present invention.

Figure 9 represents a perspective view, onan enlarged scale, of the complementary segment for usewith the segment shown in Figure 8.

Figure 10 represents a vertical cross-sectional view similar to Figure 5 but showing the mo'di: flcation composed of the segments illustrated in Figures8and 9.

Figure 11 represents a fragmentary perspective view, on an enlarged scale, of still another embodiment of the present invention.

Figure 12 represents a perspective view, on an enlarged scale, of one of the segments making up theembodiment shown in Figure 11.

Figure 13 represents a vertical cross-sectional view generally along the line 13-43 of Figure 11.

Figure 14 represents a perspective view, on an enlarged scale, of a segment forming part of another embodiment of the presentinvention.

, Figure 15 represents aperspective view, onan enlarged scale, of the complementary segment employed with the segment shown in Figure 14.

Figure 16 represents a vertical cross-sectional view of the'embodiment constructed with the segments shown in Figures 14 and 15.

Figure 1"! represents a fragmentary perspective view of another embodiment of the present invention generallysimilar to the embodiment shown in Figures 8, 9 and 10 but having the elongated ears extending generally circumferentially instead of radially.

Figure .18 represents a view similar to that of I Figure 1'7 but showing a further modification in which the circumferentially extending elongated ears are struck from the radially inner edge of. the segments.

In one'embodiment oi the present invention, shown generally in'Figules 1 to 7 inclusive, 1

' may provide aplurality of interchangeable segments indicated generally by the numeral 20. The segments 20 are constructed of sheet metal or the like suitably formed, bent and folded.

. Each segment 20 include a base 2| and a *1 pair of convergingsides It formed integrally and providing a gap 24 be- I said sides 22.

tween the free ends 2: of said sides :2. Thus,

with the base 2| being formed generally along lines of radius of the cylinder in which the ring is adapted to be used; Thus. the outeror cylinder-contacting edge 22 has a greater circumferential dimension than the inner edge 22 as shown in Figures 1, 3 and 4. Y

The free ends 22 of the sides 22 also converge radially and extend generally parallel to the ad- .lacent fold-lines 22 forming the iunctures oi the sides 22-with the base 2|. 7 I

A pair of ears 22 are struck out of the base 2| and extend generally axially inward therefrom; the ears being generallyparallel to the adjacent sides 22 and being separated therefrom by a distance corresponding to the thiclmess of Op nings 22 are formed in the base 2| corresponding to the ears 22. A pair of ridges 21" are formed on the outer surface 28 of each side 22 and extends generally axially along said side 22 from the free end 22 thereof. Corresponding grooves 22 are formed on the inner surface 22 of the sides 22. The

. ridges 21 and grooves 22 are generally axially tapered, being widest and deepest at the free end 22 and be'comingnarrowerand shallower as the ridges and grooves extend alongthe side 22. Thus, as shown in Figure 7, the clearance between the pair of ridges 21 is smallest at the free end 22.

The outer cylinder-contactingedge 22 of the segment 22 is given a convex curvature corresponding to the curvature of the .wall of the cylinder in which the piston ring is to be. used.

Thus the outer cylinder-contacting edge 22 of each segment 22 is adapted to make snug contact with the cylinder wall continuously along the.

three-sided edge'. Theinner edge 22 of the se ments 22 maybe given a concave curvature or may beleft as plane edges. 2

As .shown in Figure 5, the fold-line 22 are generally rounded interiorly ,ot the segment 22. The radially outermost edgesa22a of the i'old-' lines 32 are formed as squareshoulders by coin-- ing or other similar operation during the bending of the segments 22 so that adjacent portions 32-41 abut each other for an appreciable axial distance as shown in Figure 6. This provides more or less continuous upper and lower cylin-' der-contacting ribs or wiper edges when thepiston ring is assembled on the piston in the 0571- inder.

The composite .piston ring of the presentinvention is assembled by interlocking the segments .22 as shown generally'in Figure 2- h is, the

segments are arranged with their free ends 22 pointing alternately up and down. Adjacent sides 22 of the segments 22 are then hooked within the adjacent oppositely-extending pegments; the ears "fitting between the pairs of ridges 21 to 'hold the interconnected segments against radial movement. Theears 22 arefgiven a looseflt between the ridges 21 so that asmallamount of radial movement of the seg ents s ments 22 are fully assembled, a generally continuous ringis formed. That is, there is no Due to the resilience of the sheet. metal segments 22, the assembled piston ring has an inherent l0 resilient tension which tends to expand it radially and circumferentially. Inthis way, there is no need for a separate expander spring, as is usually required-with conventional oil-control piston rings. The piston ring may be assembled 15 in the groove 22 of a piston 22 of conventional construction having oil-drain passageways -21'ex-' tending radially from the groove 35 to the inside of the piston -22.- The outer cylinder-contacting edge 22 of each of the segments 22 fits snugly against the wall 28 of the cylinder 22.

During axial movement of the piston 32 within the cylinder 29, oil is wiped from the wall 28 of the cylinder 22 by the cylinder-contacting edges 22 and is sent through the passageways 5 3| of the segments 22, the groove 25; and the oil-drainpassageways 21 and is returned tothe crank-case thus permitting lubrication of the cylinder wall. I v

The segme ts 22 are composed of sheet metal "or other sui ble material and are formed by suitable stamping, punching, V bending, coining,

- grinding and/or other manufacturing steps in any desired sequence.

Another embodiment of the present invention ment, segments "-11 and, 22-b are employed which are generally the same as the segments 22 shown in Figures 1 to 7 inclusive; Each of the segments 22-a and 22-b is composed 01 a base 2|, converging sides 22 having free ends 23 having a gap 22 therebetween. Ears 25 are struck from the base- 2|; leaving openings 22 therein similar to the corresponding parts of the segments 22. ,However, the segment 22-a and 4 22-12 do not have ridges and grooves formed therein but, instead,an inwardly-extending button 21, and corresponding] depression 28, are formed on each of the sides 22 of the segment and corresponding depression 22, are formed on .each of the sides 22 of the segment 22-b.

When the segments 22-a and 22-b are assembled, as shown in Figure 12, the inwardlyextending button 21 of the segment '22-a fits within the depression. to or the segment 211-6.

7 over one mother as shown m Figure 2 so that Figures 1 to 7.- The radially outercylinder-coneach side 22- of each segment 22 is enclosed tactingedges 220! the segments 22a and 22-11 are convexly-roun'ded to conform to the wall of the cylinder. The radially inner edges 52 may be concavely rounded or may be left plane.

sides 22 and the base 2| are again tapered radially inwardly, being formed along lines of radius corresponding to the size of cylinder in which h piston ring is to be used. The free ends 22 of "75 the sides, 22 are correspondinglyradially tapered 22-a while an outwardly-extending button 25,

' ,iree end or gap" as'is the case with con-' 35 is shown in Figures 8, 9 and 10. In t'his embodii The fold lines. forming the juncture of the 1 wall is also sion 68 (similar to flat shoulders The method of assembly of the embodiment shown in-Figure' 10 is generally the same as that described hereinabove in connection with the embodiment of Figures 1 to 7. However, "since segments 40-0 and 40 b are not identical, they cannot be interchanged and must be assembled in their proper position.with the free ends 43 of the sides 42 thereof extending respectively downward and upward. The segments 4ila' and 40-h again may be constructed by suitable forming steps in any desired sequence.

The operation of the embodiment shown in Figures 8, 9 and 10 is generally the same as that described hereinabove bodiment of Figures 1 to "I.

Still another embodiment of the present invention is shown in Figures 11, 12 and 13. This enibodimentcorresponds generally to the embodiment of Figures 1 to '7 except that the converging sides 55 of the segments 58 terminate short of That is, the radially outermost edges 59 of the sides 55 terminate short of the outer'edge 58 ofthe base 51. Thus, as shown in Figure 13, theouter-edges 59 of the sides I 55 are recessed from the cylinder wall when the piston ring is assembled;' the only contact between the pisipn ring and the cylinder wall being along the generally continuous axially-separatedribs formed by adjacent edges 56 of the bases 51. The edges it are suitably convexly rounded to conform to the cylinder -wall, while it is no longer necessary to round the outer edges 59 of the sides 55.

The embodiment shown in Figures 11, 12 and 13 I may, in some respects-be preferred since the reduction in conta'ct-area between the piston ring and the cylinder wall reduces friction and wear and increases the unit pressure of the piston ring against the cylinder "wall. In this grooved embodiment, the problem of grinding the outer cylinder-contacting edge to conform to the cylinder straight edge need be ground upon each segment. In Figures 14, 15 and 16, there is other embodiment of the present invention in which segments Bil-a and 60-47 correspondinggenerally to the segments 40-0. and40-b, as shown in Figures 8, 9 and 10, are modified so that the sides 6| thereof terminate short of; the base '82. That is, the radially, outer edges 63 of the sides 6| terminate short of the convexly rounded radially outer cylinder-contacting edge 64 of the base' 62. Thus, the only contact between the piston ring and the cylinder wallis along the generally continuous axially-separated annular ribs formed by adjacent edges 64 of adjoining bases 62. Each of the segments Gil-a has an inwardlyextending button 61 and corresponding depresthe button 41 and depression 48 of the'embodiment shown in Figures 8, 9 and 10) while each of the segments "-1) has an outwardly-extending button 68 and corresponding in connection with the emsimplified since merely a single shown ani I and 1'5b are struck from .the radially outermost edge 66 of the base 51.

. said egments being pended claims rather depression 10 (similar to as shown in" the embodiment of- Figurest, 9 and 10, each of the segments ll-a and Ii-b is provided with a single elongated trapezoidal ear 12 which is struck out from the base 13 and is folded axially inward along a fold-linevwhich extends generally. circumferentially of the piston ring, or,

more accurately, chord-wise of said piston ring; a corresponding opening I8 being formed in said .base '13.

When the segments 1 l-a and I l-b are assembled, the slanted ends of the axially inwardly extending trapezoidal ears 12 serve as an abutment for the converging sides I4 of the adjacent dovetailed interlocked segments.

In Figure 18 there is shown another embodiment of the present invention which is identical with the embodiment of Figure 17 in all respects exceptthat the elongated trapezoidal circumfer- 16 of the segments 15a the radially inner edge of the bases 11 so that, instead of having an opening in the base, the embodiment of Figure 18 has a trapezoidal indentation 19 formed at the radially inner edge thereof.

entially extending ears Formation of the car along the radially inner edge of the base instead of at an intermediate point thereon has the advantage of requiring a simpler forming operation.

It is, of course, obvious that the ear formation I shown inFigures 1'7 and 18 could be employed equal y wellwith the embodiments shown in Figures 2, 11 and 14 without departing from the spirit of the present invention.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore. desired ,that the present embodiments .be considered in all respects as illustrative and not restrictive, reference being bad to the apscription to indicate the scope of the invention.

Having thus described the invention, whatis hereby claimed to be new and desired to besecured 'by Letters Patent is:

1. An oil-controLpiston-rrng comprising a pin-- rality of individual cireumferentially-disposed segments of sheet metal or the like bent and folded generally axially to provide radially-extending oil-passageways therethrough, each of separably' engaged in circumferentially-fixed relationship with its adjoin-- ing segments to provide a generally continuous annulus.

2. Anoii-control piston-ring comprising a plurality of individual circumferentially disposed segments of sheet metal or the like, each of said segments having a base and having a pair of converging free sides and being open at the radial edges, thereof thereby to provide a cross-sew tionally-triangular sageway therethrough, ing separably engaged the button 49 and depression 50 of the embodiment shown in Figures 8. 9 and 10).

sembled, the buttons than to the foregoing deradially-extending oil-pas-' I by to provide a, more disposed with their free continuous annulus, said free sides for of each segment overlapping the sides of adiadisposed with their free sides extending in opposite axial directions,

segments being interlocked to provide a generally cent segments thereby to interlock said segments .and to provide a generally continuous annulus.

4. An oil-control piston-ring comprising a plurality of individual circumferentially-disilosed segments of sheet metal or the like suitably bent and folded to provide radially-extending oil-passageways therethrough.. each of said segments. having a pair ofgenerally a'xially-extendingfree sides, the free sides 01' each of said segments overlapping the sides of adjacent segments thereorless continuousring. 5. An oil-control piston-ring comprisinga plurality of individual circumi'erentially-disposed segments formed of sheet metal or the like, each of said segmentshaving a base disposedin a generally radial plane and having a pair of free sides formed integrally with said base and extending generally axially therefrom, said base and said free sides enclosing a generally radially-extending oil-passageway, successive segments being disposed with their free sides extending in opposite continuous annulus, and interengaging means carried bysuccessive segments for limiting the relative radial movement of individual segments. 9. An oil-control piston-ring comprising a pinrality .of individual circumferentially-dispased segmentsformed of sheet metal or the like, each A of said segments having a base disposed in a generally radia1 plane and having a pair of converging sides formed integrally with said :base.

and extending generally axiallytherefrom, said base and said converging sides enclosing a cronsectionally-triangular generally radially-extending oil -passageway, successive segments being disposed with their free sides extending in opposite axial directions, the free sides of successive segments being interlocked to provide a generally continuous annulus, and complementary protuberances and depressions formed on the interlocked free sldes of successive segments for limiting the relative radial movement thereof.

10. An oil-control piston-ring comprising a v plurality ofindividual circumferentially-disposed segments formed of sheet metal or the like, each of said segments having a base disposed in a generally radial, plane and having a pair of converging sides formed integrally with said base and extending generally axially therefrom, said, base and said converging sides enclosing a crosssectionally-triangular generally radially-extend- 'ing oil passageway, successive segments being axial directions, the free sides of successive segments being interlocked to continuous annulus.

6. An oil-control piston-ring comprising a plurality of individual circumferentialhr-disposed segments formed of. sheet metal or the like, each provide, a generally of said segments having a base disposed in a generally radial plane and having a pair of converging sides formed integrally with said base and exdisposed with theirfree sides extending in opposite axial-directions, the free sides of successivesegments being interlocked to provide a enerally continuous annulus, and a pair of ears struck inwardly from the base of'each'segment. said ears extending generally parallel to the adjacent free sides and spaced therefrom thereby partially to enclose; the free ends oi. the interlocked sides of adjacent segments.

tending generally axially therefrom, said base and said converging sides enclosing a cross-sectionally-triangular' generally radially-extending oil-passageway, successive segments being disposed with their free sides extending in opposite axial directions, the free sides of successive segments being interlocked to provide a generally continuous annulus. I a 7. An oil-control piston-ring comprising a plumay of, individual circumferentially-disposed segments formed of sheet metal or the like, each of saidsegments having a-base disposed in a generally radial plane and having a pair of free sides formed integrally with said base and 'extendins generally. axially. therefrom, said base and said free sides enclosing a generallyradially-extending oil-passageway, successive segments being sides extending in opposite-axial directions, the free sides of successivesegments being interlocked to provide a generally and means provided upon limiting the relative radial movement of said individual segments.

8. An oil-control rality of individual circumferentially-disposed segments formed ofsheet-metal or the like, each of said segments having a base disposed in a generally radial plane and having a pair of converging sides formed integrally with said base :2; extending generally-axially therefrom, said sectionally-triangular generally radially-extending oil-passageway, successive segments being axial-directions,

and said convergingsides enclosin'g a cross- 1'1. Anoil-control piston-ring comprising a plurality of individual circumferentially-disposed generally radial plane and having a pair of con-' segments formed of sheet metal or the like, each of said segments having-a base disposed in a verging ,sides formed integrally with-said base and extending generally axially therefrom, said 1 base and said converging sides enclosing a cross.- sectionally-triangular generally radially extending oil-passageway, successive segments being disposed with their free sides extending in opposite axial directions, the free sides of successive segments being interlocked to provide a generally continuous annulus, a pairof cars struck inwardly from the base of each segment, said ears extending generally parallel to the adjacent free 7 sides and spaced therefrom thereby partially to piston-ring comprising a plu- 85 pered, successive enclose the free ends of the interlocked sides of adjacent segments, 'and a pair'of spaced axiallyextending outwardly-pressed ridges formed at the free end of each of said sides, said pair 'oil ridges and said ears cooperating tolimit relative radial movement of individual segments.

12. An oil-control piston-ring co mprising a plurality of individual circumferentially-dispoeed segments. formed of sheet metalv or the like, each having a base lying in a generally radial plane and a pair of converging free sides formed inte'grally-with said axially therefrom, said base being radially tair' free-ends extending in alternate oppodte the free sides of successivebase and-extending generally segments being disposed-with thefree sides of adiacent pee;

ternal combustion engine, comprising aplurality of individual circumferentially-disposed segments formed of sheet metal or the like havin open radially inner and radially outer edges thereby to provide a radially-extending oil-passageway therethrough, each of said segments being'separably engaged with its adjoining segments in circumferentially-fixed relationship to provide a generally continuous annulus, theouter radial .edges of said segments being convexly curved to .conform to the wall of the cylinder.

14. An oil-control piston-ring comprising a plurality of individual circumferentially-disposed segments formed of-sheet metal or the like, each having a base lying in a generally radial plane and having. a pair of free sides formed integrally with said base and extending generally axially therefrom, said segments being open at the radial edges thereof .to provide oil-passageways .therethrough, the free sides of adjacent segments being interlocked to provide a generally continuous annulus, the outer radial edges of the free sides being recessed from the outer radial edges of said base.

15. A self-expanding oil-control piston-ring for use on a piston within a cylinder of an internal through v 18. An oil-control piston-ring comprising a plurality of individual cireumferentially-disposed segments formed ofsheet metal or the like, each of saidsegments having a base disposed in a generally radial plane-and having a pair of convergingfree sides formed integrally with said base and extending generally axially therefrom, said combustion engine comprising a plurality of individual circumferentially-disposed segments, each having a base lying in a generally radial plane and having a pair of converging free sides formed integrally posite axial-directions, the free sides of adjacent with said base and extending generally axially therefrom, said segments being base and said converging sides forming a crosssectionally-triangular generally radially-extending oil-passageway, each of said segments having an ear struck inwardly from said base and extending generally axially therefrom, saidear being spaced apart fromsaid converging sides; successive segments being disposed with their free passageways extending generally radially them-'- sides extending in opposite axial directions, the free sides of successive segments being interlocked to provide a generally continuous annulus, the free ends of the interlocked sides being enclosed and supported by the inturned ears.

19. An oil-control piston-ring comprising a plurality of individual circumferentially-disposed segments formed of sheet metal or the like, each of said segments having a base disposed in a generally radial plane and having a pair of converging free sides formed integrally with said,

base and extending generally axially therefrom, said-base and saidrconverging' sides forminga cross-sectionally-triangular generally radiallyextending oil-passageway',. eac h of said segments having a generally trapezoidal ear struck inwardly from said base and extending generally axially therefrom with the slanted ends of said ear ex- 351 tending generally parallel to. the adjacent free segments being interlocked to 'provide a generally continuous annulus, the outer radial edges of the free sides of each segment being recessed fromthe outer radial edge 01 the base thereof, the outer radial edges of the bases of alternate segments forming a pair of generally continuous axiallyspaced cylinder-contacting ribs.

16. An oil-control piston-ring comprising a plurality of individual circumferentially-disposed segments, each having an oil-epassageway extend:

ing generally radially therethrough, each of said segments being separably engaged with its adjoining segments in circumferentially-flxed rela- Qtionship to provide a generally continuous annu- 17. A self-expanding oil-control piston-ring comprising a plurality of circumferentially-disposed segments of sheet metal or the like interlocked in circumferentially-flxed relationship to form a generally continuous annulus having oilsides and spaced apart therefrom; successive segments being disposed with their free sides extending in opposite axial directions, the free sides of successive segments being interlocked to provide a generally continuous annulus, the free ends of the interlocked sides; being enclosedand supported by the slanted sides of the cars.

20. An. oil-control piston-ring comprising I a.

plurality of individual circumferentially-di'sposed segments formed of sheet metal or the like; each or said segments having-a base disposed in a generally radial plane and having a pair of converging free sides formed integrally with said base andextending generally axially therefrom, said base and said convergingsides forming a crossse'ctionally-triangular generally radially-extendtheir tree sides extending in opposite axial directions, the free sides of successive segmentsrbe- 'ing interlocked to provide a generally continuous annulus, the free ends of the interlocked sides being enclosed and supported by the inturned ears;

. WILLIAM S. LOEB. 

